Tissue graft

Abstract

The present invention relates to a method of preparing a tissue graft material. The invention also relates to a multipurpose tissue graft material and to methods of using same as a replacement for vascular and non-vascular tissue.

1. A method of preparing an arteriovenous graft consisting essentially of:
 i) washing a starting tissue obtained from a human or animal ureter with at least one bioburden reducing agent so that said starting tissue is disinfected, 
 ii) decellularizing the disinfected tissue resulting from step (i) with a solution that lyses cells of said disinfected tissue so that a decellularized tissue matrix is formed, 
 iii) contacting said decellularized tissue matrix resulting from step (ii) with at least one nuclease so that nucleic acid associated with said decellularized tissue matrix is degraded, and 
 iv) washing said decellularized, nuclease-treated tissue matrix resulting from step (iii) so that cellular or extracellular debris is removed and said arteriovenous graft is obtained. 
 
     
     
       2. The method according to  claim 1  wherein said at least one bioburden reducing agent is an antimicrobial agent. 
     
     
       3. The method according to  claim 1  wherein, in step (ii), sterile water is used to decellularize the disinfected tissue resulting from step (i). 
     
     
       4. The method according to  claim 1  wherein, in step (ii), an aqueous hypotonic buffer is used to decellularize the disinfected tissue resulting from step (i). 
     
     
       5. The method according to  claim 1  wherein, after step (iv), said arteriovenous graft is sterilized. 
     
     
       6. The method according to  claim 1  wherein, after step (iv), said arteriovenous graft is cryopreserved. 
     
     
       7. An unfixed decellularized arteriovenous graft produced by a method consisting essentially of the steps of:
 i) washing a starting tissue obtained from a human or animal ureter with at least one bioburden reducing agent so that said starting tissue is disinfected, 
 ii) decellularizing the disinfected tissue resulting from step (i) with sterile water or an aqueous hypotonic buffer that lyses cells of said disinfected tissue so that a decellularized tissue matrix is formed, 
 iii) contacting said decellularized tissue matrix resulting from step (ii) with at least one nuclease so that nucleic acid associated with said decellularized tissue matrix is degraded, and 
 iv) washing said decellularized, nuclease-treated tissue matrix resulting from step (iii) so that cellular or extracellular debris is removed and said arteriovenous graft is produced. 
 
     
     
       8. A method of treating a patient in need of an arteriovenous graft comprising introducing into said patient an unfixed, decellularized arteriovenous graft that is obtained by the method according to  claim 1 . 
     
     
       9. A method of treating a patient having a defective vein or artery comprising replacing said defective vein or artery with said arteriovenous graft according to  claim 7 . 
     
     
       10. The method according to  claim 9  wherein said patient has a defective vein. 
     
     
       11. The method according to  claim 9  wherein said patient has a defective artery. 
     
     
       12. The method according to  claim 1  wherein said at least one nuclease is DNAse I and RNAse A. 
     
     
       13. The arteriovenous graft according to  claim 7  wherein said at least one nuclease is DNAse I and RNAse A.